How to change SQL Server Instance Name?

Query current Instance Configuration

1. sp_helpserver
2. select @@servername

Execute the below query to change the instance name

1. sp_dropserver 'OldName'
2. go
3. sp_addserver 'NewName' , 'local'
4. go

Vefiry SQL Server Instance Config. by running following queries.

1. sp_helpserver
2. select @@servername